As corporate buyouts go, eBay's 2005 acquisition of Skype has been panned as a bad deal. In October, eBay said it would take a massive write-off because it had overvalued the internet phone company, whose revenues have been soft. As a consumer service, though, Skype is a success, and it's likely to become even more popular. In the fourth quarter of 2007, the company added about 30 million subscribers, bringing its total to 276 million worldwide.

Skype technology converts telephone conversations into digital information packets, transmits those packets across the internet, and then reassembles them-for free. (That's where the soft revenues come in.) Until recently, Skype calls had to be made from a computer with an internet connection. But as WiFi hotspots have spread, a handful of companies now offer wireless devices that work on the road. If you're calling another Skype user, the service costs you nothing. If you call someone with a traditional landline, the service is still relatively inexpensive, with international rates starting at 2.1 cents a minute.

You do, however, have to purchase calling time in advance (go to skype.com). The service lets you choose up to 10 numbers for your phone, using any area codes. (One caveat: You can't use these in an emergency, as they don't connect to 911 operators.) We tried four of the newest devices.

1. Belkin Wi-Fi Phone, $180

THE GOOD: Connecting to open WiFi hotspots is easy, and the sound quality is almost as good as a landline's. Like the other products listed here, the phone itself can be used to create a new Skype account.
THE BAD: This model doesn't have the ability to access hotspots that require a fee or a browser, which is a problem at most hotels.

2. Nokia N810 Internet Tablet, $480

THE GOOD: More like a handheld computer than a mere phone, the Nokia comes with a music player and has email and video-conferencing capability. Our favorite of the group.
THE BAD: The sound is too low, even at maximum volume. Also, the bulky design makes it uncomfortable to hold during long conversations.

3. Panasonic KX-WP1050, $360

THE GOOD: Specifically designed for business travelers, it comes with a base unit that lets you set up your own hotspot, which you can use with your laptop and any other WiFi-enabled device, not just the phone.
THE BAD: For this price, Panasonic should have included a Web browser.

4. Netgear SPH200W, $150

THE GOOD: It comes with a preset log-in for T-Mobile hotspots, which are increasingly common at airports and hotels across the country.
THE BAD: Its diminutive size (4.1 inches by 1.7 inches by 0.8 inches) makes the phone feel flimsy. Also, as with the Panasonic, the screen is too small.